Five SIM cards on the first plan costs £36 per month, or £7.20 each and five cards with the 15GB data tariff costs £69 per month, or £13.80 each.

So, rather than having a contract for each parent separately and then contracts for each child in a house, for example, BT is offering a way to get everything on one contract, but offering each SIM individual allowances.

Furthermore, there are controls for each SIM, so the main bill payer gets parental controls so that those other SIMs don't get free roaming access, unless that's allowed.

The first SIM in a plan has to be on a 12 month contract, but each additional SIM is on a 30 day rolling contract, so you can add and remove them depending on each member's needs. The new Family SIM can be combined with handsets too, depending on your needs.

BT's Family SIM plan is available to sign up for now, either as SIM-only or included with phones from BT's online store.